Skip the auto shop - Our mechanics make house calls

Q: My car is showing two trouble codes: P1639 and PO452

asked by on

Need to repair the two codes PO452 and P1639 in order to pass emissions

My car has 81000 miles.
My car has an automatic transmission.

Hello. The diagnostic codes you are receiving may be a result of both sensors failing, or a power supply issue. The code P1639 stands for an A/C refrigerant pressure sensor voltage shortage. The second code P0452 stands for the fuel tank pressure sensor voltage shortage. While it’s possible that both sensors can fail at once, it’s also possible the voltage references are being disturbed. You can attempt to replace the fuel pressure sensor and refrigerant pressure sensor and see if the codes go away. You can also trace the voltage with a voltmeter in order to find where the voltage drop occurs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Truck not starting - 2002 Chevrolet Trailblazer

Hi there, thanks for writing in about your 1992 Dodge Spirit. A slow cranking motor can definitely impede a motor from starting. First thing you need to do is connect a battery charger and get the cranking speed up. As...

Q: I have an intermittent misfire - 2002 Pontiac Grand Prix

Hi and thanks for contacting YourMechanic. The EGR can cause a misfire if it is stuck open when the engine is cold or running at a lower speed. The EGR replaces some of the air with burnt fuel to help...

Q: Key turns, no crank

The starting system is rather simple. There are only a few components that can cause this to happen. The first place to check is with the starter. They can fail intermittently and this is a sign that it is going...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.